1. Field of the Invention
This invention relates in general to apparatus for drilling holes and more particularly to a construction drill set for use with a conventional drill and chuck which features a self feed pilot bit and easily changed drill bits capable of drilling relatively large size holes.
2. Discussion of the Prior Art
The present invention relates to drilling relatively large holes in wood or other material. In construction of buildings, many 1"-3" holes are required which in many cases need to be made through more than one 2" plate. Conventional drills use auger bits which remove all of the workpiece material within the boundaries of the hole as chips. Several problems are inherent in the conventional system. Self-feeding auger bits have the diameter of the required hole size, and remove the entire hole area from the workpiece, as mentioned above. These devices require a larger amount of torque as the size of the hole increases. As the size of the hole increases and the hardness of the workpiece increases, large amounts of torque are required from the drill motor. At certain hole sizes and materials, the drill generates too much torque for the operator to continue drilling and yet hold onto the drill itself. This problem occurs whether the drill uses a conventional auger or planetor type bit. This conventional drill system, put in another way, will drill large holes at a relatively low RPM because of the high torque requirements. The hole is then drilled slower than desired. Other problems occur due to the generation of wood chips by the bit which when larger holes are drilled, the drill bit must be periodically removed and the chips removed to facilitate drilling especially for deep holes. Obviously, in these drilling systems, the generation of chips from the workpiece material means that periodic cleanup is necessary, which adds to the overall job time involved in most situations. It should also be noted that individual drill bits need to be stored separately from the drilling apparatus and in many cases time is expended searching for the proper bit required.
Another set of problems from conventional bits occurs when partial or overlapping holes are desired. To elaborate further on this problem, if a trifolium design is required generated by drilling three overlapping holes, conventional drill bits will produce tears at the overlapped corners. This application occurs especially when holes for large pipes are required. Further, occasionally holes may have to be drilled through more than one plate and then through a sheetrock nailer only partially overlapping the plates. Conventional drill bits will drill through the 2.times. plates, for example, but then "grab" the sheetrock nailer as it does not fully extend over the drilled hole. The present invention addresses the above mentioned problems and provides a system which reduces or eliminates shortcomings of the prior art.